A cataract is a clouding of the lens in an eye which leads to a decrease in vision and can eventually lead to blindness. Surgery is needed if the cataracts are causing problems and generally results in an improved quality of life. Conventional cataract surgery involves removing the cloudy lens in an eye and replacing it with an artificial lens. However, conventional artificial lenses have a fixed focal length which may limit an individual's ability to focus on objects of varying distance.
Cataracts are most commonly due to aging, but may also occur due to trauma, be present from birth, or occur following eye surgery for other problems. More than half the people in the United States have had cataracts by the age of 80. Techniques and devices that can help individuals offset the effects of cataracts are increasingly in demand.